MOLECULAR-DYNAMICS SIMULATION OF REACTIVE ION ETCHING OF SI BY ENERGETIC CL IONS

We report results from molecular dynamics simulations of the etching o f a Si surface by energetic Cl atoms (15 eV less than or equal to E le ss than or equal to 200 eV). We find that the energy dependence of the Si yield (number of Si atoms desorbed per incident Cl ion) is in reas onable agreement with recent experiments and with previous simulations performed up to 50 eV. We also investigate the variation of the Si yi eld with the impact angle of incidence, the stoichiometry of the desor bed material, and the effect of a thermal background Cl flux to the su rface in the presence of an ion flux at 50 eV. Surface roughening due to etching was observed and the calculated rms roughness is in reasona ble agreement with experiments. (C) 1997 American Institute of Physics .